Base station apparatus, wireless communication system and frequency assignment method

A wireless communication system comprising:

• a first mobile station;
• a plurality of second mobile stations;
• and
• a base station apparatus that communicates with the first and second mobile stations,
• wherein the base station apparatus comprises:
• a first wireless communication circuit that communicates with the first mobile station employing a first frequency band that is preferentially assigned to the base station apparatus;
• a plurality of second wireless communication circuits that communicates with the second mobile stations employing at least one of a plurality of second frequency bands that are preferentially assigned to other apparatuses;
• a frequency detection unit that detects the usage of the second frequency bands by periodically detecting the electrical power of the second frequency bands in the second wireless communication circuits;
• a detection result storage unit that stores a history of the usage of the second frequency bands detected by the frequency detection unit;
• a communication status storage unit that stores a communication status including an average communication frequency of information data per unit time during the communication with the first and second mobile stations;
• and
• a frequency change control unit that determines if there is any unused second frequency band that is not used by other apparatuses and also for the communication with the second mobile station, based on the history of the usage of the second frequency bands stored in the detection result storage unit, and that changes the frequency for the communication with the first mobile station from the first frequency band to the unused second frequency band, based on the determination result of the unused second frequency band and the communication status for the first mobile station stored in the communication status storage unit, and
• wherein each of the first and second mobile stations comprises:
• a third wireless communication circuit that communicates with the base station apparatus employing the first frequency band;
• and
• a fourth wireless communication circuit that communicates with the base station apparatus employing at least one of the plurality of second frequency bands.

A method for assigning a frequency to be used for a wireless communication between a base station and a first mobile station,

• wherein the base station is configured to communicate with the first base station employing a first frequency band that is preferentially assigned to the base station, and to communicate with a second mobile station employing at least one of a plurality of second frequency bands that are preferentially assigned to other apparatuses, and
• wherein the method comprising:
• detecting the usage of the second frequency bands by periodically detecting the electrical power of the second frequency bands;
• storing a history of the detected usage of the second frequency bands;
• calculating a communication status including an average communication frequency of information data per unit time during the communication with the first and second mobile stations;
• determining if there is any unused second frequency band that is not used by other apparatuses and also for the communication with the second mobile station, based on the stored history of the usage of the second frequency bands;
• and
• assigning the frequency for the communication with the first mobile station from the first frequency band to the unused second frequency band, based on the determination result of the unused second frequency band and the calculated communication status.